Process of spinning textile fibers

ABSTRACT

Air-permeable collecting surface means are continuously moved. Suction is produced on said collecting surface means in a predetermined suction zone, which has an abrupt boundary in the direction in which said collecting surface means depart from said suction zone. A stream of air is thus produced, which is directed toward said suction zone. Fibers are entrained in said stream so that the latter carries said fibers to said suction zone and the fibers are twisted together adjacent to said boundary by the components of force which are due to the movement of the collecting surface and said suction. The resulting twisted fibers are held against rotation and are doffed in the form of a thread from said collecting surface means transversely to the direction of movement thereof.

Fehrer PROCESS OF SPINNING TEXTILE FIBERS [76] Inventor: Ernst Fehrer, Auf der Gugl 28, Linz, Austria [22] Filed: Jan. 7, 1974 [21] Appl. No.: 431,041

[30] Foreign Application Priority Data Jan. 17, 1973 Austria 346/73 Oct. 5, 1973 Austria 8501/73 [52] US. Cl 57/156; 57/58.89 [51] Int. Cl DOlh H12 [58] Field of Search 57/58.8958.95, 50, 156

[56] References Cited UNITED STATES PATENTS 3,343,360 9/1967 Brown 57/58.9l 3,635,006 1/1972 Fehrer 57/156 X 3,636,693 l/l972 Benson et al. 57/58.95

[ 51 Aug. 12, 1975 Primary Examiner.lohn Petrakes Attorney, Agent, or F irm-Kurt Kelman 57 ABSTRACT Air'permeable collecting surface means are continuously moved. Suction is produced on said collecting surface means in a predetermined suction zone, which has an abrupt boundary in the direction in which said collecting surface means depart from said suction zone. A stream of air is thus produced, which is directed toward said suction zone. Fibers are entrained in said stream so that the latter carries said fibers to said suction zone and the fibers are twisted together adjacent to said boundary by the components of force which are due to the movement of the collecting surface and said suction. The resulting twisted fibers are held against rotation and are doffed in the form of a thread from said collecting surface means transversely to the direction of movement thereof.

1 Claim, 3 Drawing Figures PATENTED 1 21975 3,898,788

F/GJ 2 \N PROCESS OF SPINNING TEXTILE FIBERS This invention relates to a process of spinning textile fibers, in which the fibers fly in a directed stream as they are fed to a spinning station and the spun thread is held against rotation as it is doffed.

In a known process of that kind, the fiber material is disintegrated into individual fibers, which are blown into a hollow drum or the like, which rotates at high speed and in which the fibers are collected under the action of centrifugal force on the inside periphery of the drum or the like and fibers are subsequently centrally doffed from the drum or the like so as to form a thread. The equipment required to carry out this process involves a relatively high structural expenditure and the main disadvantage resides in that the number of turns per inch of the fibers of the spun thread is limited by the speed of the drum or the like. Because said speed cannot be increased above a certain limit for structural reasons, the production rate is also limited because the doffing speed of the spun thread can be increased only if the spinning speed is correspondingly increased.

In another known process the individual fibers are blown into a shallow channel, which is formed in a deck over which an endless belt revolves transversely to the channel. That process relies on the fact that a fibrous structure can be twisted together or spun between two surfaces which move relative to each other if these moving surfaces have doffing means associated with them by which the fibrous structure is continuously doffed transversely to the direction of movement of the surfaces and which prevents a rotation of the fibrous structure. The channeled deck together with the endless belt moving thereover may be replaced by two parallel superimposed endless belts, which revolve in the same direction and whose confronting courses form the two surfaces that extend transversely to the longitudinal direction of the thread. The material is supplied to the belts on one longitudinal side thereof and is doffed through an eyelet or the like on the other longitudinal side. That process has the advantage that the fibers can be twisted together at high speed so that the thread can be doffed at high speed too as the thread is very small in diameter and because belt velocities can be used which can well be controlled and, on the other hand, high spinning speeds can be produced as the thin thread rolls on the belt which is moving thereover. Difficulties have arisen, however, in connection with the air which is blown to feed the fibers and which cannot be properly discharged and because the air stream acting on the fibers from behind in the deck channel and between the moving endless belts causes the fibers to be virtually upset and prevents an adequate parallelization thereof.

It is an object of the invention to eliminate all these disadvantages and to provide a process which is of the kind defined first hereinbefore and which enables a spinning at very high twisting speeds and doffing velocities without need for complicated equipment having parts which move at excessively high velocities or speeds of rotation and without giving rise to difficulties as regards an upsetting or inadequate parallelization of fibers.

This object is accomplished according to the invention in that the approaching flying fibers are sucked in a narrow zone against a continuously moving, airpermeable collecting surface in a zone which has an abrupt boundary at the end from which said surface departs, and adjacent to said boundary are twisted together under the action of the components of force which are due to the movement of the collecting surface and the suction, and the fibers in the form of a thread are doffed transversely to the direction of movement of the collecting surface.

The fibers which impinge on the collecting surface in the suction zone thereof are moved by the collecting surface toward the boundary of the suction zone from which the collecting surface departs. As the fibers tend to leave the suction zone, they are returned into the suction zone by the suction so that the fibers revolve like a roll in the boundary region. The fibrous structure which is formed as a result of the roll-like revolving movement is doffed transversely to the direction of movement of the collecting surface and is held against rotation in the doffing station so that a corresponding spinning operation results. The same has the advantage that no difficulties are involved in the carrying air stream and in the discharge thereof, this air stream is even required for the spinning operation and the rolllike revolution on the collecting surface results in a desirable parallelization of the fibers. In this case too the collecting surface need not be moved at an intolerably high velocity in order to ensure a high spinning speed because the latter results from the rolling of the thin thread on the collecting surface. The collecting surface might be formed by the periphery of a vacuum drum. In that case the critical boundary of the suction zone would extend along a generatrix of the drum and a pair of doffing rolls or the like would be provided to doff the spun thread. Alternatively, the collecting surface might be formed by a revolving perforated endless belt, which moves over one or more suction inserts. In the latter case, a plurality of spinning stations may be arranged one behind the other in the direction of movement of the endless belt and may be provided each with separate fiber-feeding means and thread-doffingmeans. Alternatively, the collecting surface could be provided in the form of a rotating disc with possibly a plurality of approximately radially limited suction zones. All these arrangements are relatively simple and do. not involve difficulties in design.

The process according to the invention will be explained with reference to the accompanying drawing, which shows strictly diagrammatically arrangements for carrying out the process and in which FIGS. 1 and 2 are a vertical sectional view and a top plan view, respectively, showing the essential parts of an arrangement, and

FIG. 3 is a vertical sectional view showing an arrangement which comprises two or more spinning stations.

In the arrangement shown in FIGS. 1 and 2 the actual spinning means comprise a perforated or air-permeable carrier having a collecting surface 1 and on opposite surface 1a. A suction zone 2 is defined by a suction box 3, which is located under the surface la and is connected to a vacuum source, not shown. The carrier is continuously moved in the direction of the arrow. A wall 4 of the box 3 forms a boundary between the suction zone 2 and another zone 12 in which both surfaces 1, 1a are exposed to ambient air pressure. The collecting surface 1 might alternatively be formed by the periphery of a vacuum drum, which rotates around the suction box 3, or might consist of a horizontal disc or annular disc.

lndividual fibers fly in a directed stream, which feeds them to the collecting surface 1, and are sucked against the latter adjacent to the suction zone 2 and at the boundary adjacent to the wall 4 are twisted together under the action of components of force which are due to the movement of the collecting surface and the suction action causing a current of air to flow from the zone 12 to the suction zone 2 along the surface 1. The resulting structure is doffed in the form of a thread transversely to the direction of carrier movement by means of a pair of rolls 5.

In the arrangement shown in FIG. 3 the collecting surface 1 is formed by an endless belt, which is trained around suitable reversing pulleys 6 and revolves continuously. Two or more spaced apart spinning stations of the kind shown in FIGS. 1 and 2 are arranged one behind the other in the direction of revolution 3 of that endless belt 1. Each of these spinning stations is fed by carding means, which comprise a feeding belt conveyor 7, an inlet roll 8 provided with an overlying, invertedtroughlike cover, and a carding drum 9 rotating at high speed. The individual fibers separtated by the combing action of the drum fly off the drum under the action of centrifugal force. This departure may be assisted by air nozzles, not shown. The fibers then move in a directed stream to the suction zone 2 on the collecting surface on the endless belt 1.

What is claimed is:

1. A process of spinning textile fibers which comprises:

a. continuously moving a carrier having two opposite faces and permeable to flow of air between said two faces in a predetermined direction sequentially through a first zone and a second zone separated from said first zone by a boundary transverse to said direction;

b. applying suction to one of said faces in said first zone while maintaining equal pressure on said two faces in said second zone, whereby ambient air is caused to flow through said carrier inward of the other face thereof in said first zone, no air flows through said carrier in said second zone, and a current of air is caused to flow in a direction opposite to said predetermined direction from said second zone toward said first zone;

c. depositing textile fibers on said other face before said carrier passes said boundary from said first zone to said second zone, whereby said fibers are held to said other face by said air flowing in said first zone, are released from said other face in said second zone, and are twisted between said moving carrier and said current; and

d. withdrawing said twisted fibers from said carrier transversely to the direction of carrier movement adjacent said boundary. 

1. A process of spinning textile fibers which comprises: a. continuously moving a carrier having two opposite faces and permeable to flow of air between said two faces in a predetermined direction sequentially through a first zone and a second zone separated from said first zone by a boundary transverse to said direction; b. applying suction to one of said faces in said first zone while maintaining equal pressure on said two faces in said second zone, whereby ambient air is caused to flow through said carrier inward of the other face thereof in said first zone, no air flows through said carrier in said second zone, and a current of air is caused to flow in a direction opposite to said predetermined direction from said second zone toward said first zone; c. depositing textile fibers on said other face before said carrier passes said boundary from said first zone to said second zone, whereby said fibers are held to said other face by said air flowing in said first zone, are released from said other face in said second zone, and are twisted between said moving carrier and said current; and d. withdrawing said twisted fibers from said carrier transversely to the direction of carrier movement adjacent said boundary. 